Valve releasing gear



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VALVE (No Model.)

A. DIX RELEASI No. 548,526. Patented Oct. 22, 1895.

(No Model.) 4 Sheets-#311861; 2.

0. A. DIXON.

VALVE RELEASING GEAR. No. 548,526. Patented Oct. 22, 1895.

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0 A. DIXON. VALVE RBLBASING GEAR.

No. 548,526. Patented Oct. 22, 1895.

(No Model.) 4 Sheets-Sheet 4.

G. A. DIXON.

. VALVE RELEASILTG GEAR. No. 548,526. Patented 051:. 22, 1895.

UNITED STATES PATENT OrFicE.

CHARLES A. DIXON, OF NEVVBURG, NEW YORK.

VALVE-RELEASING G EAR.

SIPECIFICATION forming part of Letters Patent No. 548,526, dated October 22, 1895.

Application filed July 5, 1893. Serial No. 479,619- (No model.)

To whom it may concern: Be it known that 1, CHARLES A. DIXON, of Newburg, in the county of Orange, and in the State of New York, have invented certain new and useful Improvements in Valve-Releasing Gear for Steam-Engines; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, in which Figure 1 is a perspective view of my valveoperating mechanism from the front. Fig. 2 is a like view of the same from the rear. Fig. 3 is a plan view of said mechanism from the upper side. Fig. dis an elevation of the same from the rear end. Figs. 5 and 6 are respectively front and rear elevations of said mechanism. Fig. 7 is a perspective view of the parts used for pressing the knock-off lever upon the knock-0d cam, said parts being separated from each other; and Fig. 8 is a central longitudinal section of the same.

Letters of like name and kind refer to like parts in the several figures.

The object of my. invention is to increase the efficiency and durability of valve-releasing mechanism for steam-engines; and to such end my said invention consists in the construction of parts and their combination with each other, substantially as and for the purpose hereinafter specified.

My invention is especially adapted for use in connection with the style of engine known as the Corliss, in which the stem A of a rocking steam-valve projects horizontally and laterally from the steam-chest B, and has pivoted centrally thereon a lever G, that has pivoted to its upper end a connecting-rod D, which extends to and is connected with a governor, and to its lower end has pivoted in like manner a second connecting-rod D, that extends to and is pivoted upon the upper end of the knock-oft lever of the rear steam-valve. Upon the hub c of said lever is provided a knock-0ft cam c, that preferably is arranged upon the rear upper portion of said hub, as shown.

Upon the valve-stem A, immediately outside of the governor-lever O, is jonrnaled a jim-crank E, which, as seen, has two arms e and e, that are arranged nearly at a right angle to each other, to the lower of which arms e is pivoted one end of an eccentricmoved connection F, while within the outer end of the second rearwardiy-projecting arm e is journaled a shaft G, which has secured to or formed upon its front end a latch-lever g and to or upon its rear end a knock-0d lever 9'. Outside of said jim-crank there is secured to the valve-stem A the steam-crank H, which from thence extends rearward, and at its end 71. has the usual angular form, and near such end is provided with a pin h, that pivots one end of the dash-pot connection I.

The latch-lever g has the usual hook form, and its shoulder g is adapted to engage with the end it of the steam-crank H, while the end 9 of the knock-0ft lever g is adapted to be engaged with the hub c and knock-01f cam c.

It has heretofore been the custom to hold the knock-0d lever in yielding contact with the knock-ofit cam by means of a flat spring that, from a stud, extended around the hub and at its free end bore upon the outer side of the lever near its end, which spring was difficult to make and temper and was quite liable to change its strength and to break. To secure the desired result without liability to breakage and at the same time to enable the strength of the pressure of the lever upon the cam to be varied at will while the engine is in motion, I employ the following construction, viz: Secured to and extending rearward from the hub cis a bracket 1, which at its outer end furnishes a pivotal bearing for a block K. The latter at its inner end is provided with a transverse threaded opening it, through which passes a rod L, that has one end pivoted upon the contiguous side near the free end of the knock-oft lever g.

Within the outer end of the opening is inserted an exteriorlythreaded sleeve M, which at its outer end is provided with a milled head m, and interiorly has such diameter of its axial opening m as to permit of its free movement over said rod. A spiral or coiled spring N is placed around the latter with its ends in engagement with the inner end of said sleeve, and a head Zat the inner end of said rod operates to press the inner end of said knock-oft lever against the hub c and its cam c, and such pressure may be increased or diminished by moving said sleeve inward or outward. In order that the jar or vibration of the parts when in motion may not change the adjustment of the sleeve, a jam-nut m is placed upon the latter and screwed down upon the contiguous face ofthe block K.

The mechanism is now complete and operates in the usual manner, the jim-crank being rocked by the action of an eccentric, so as to cause the latch-lever to engage with and move the steam-crank, while the governor-lever is,

t by the action of the governor, moved so as to change the circumferential position of the knock-off cam and cause the said latch-lever to be released at such point of the stroke of the piston as the necessities of the caserequire in order to maintain a uniform speed of the engine.

It will be'seen'that-in consequence of the use of separate latch and knock-off levers, instead of having one lever perform both offices the governor connections are placed in rear of all cranks next to the cylinder and the valve stem materially shortened, while all of the parts are given greater freedom of motion.

Having thus described my invention, what I claim is- 1. As an improvement in valve gear, the combination ofthe knock-off cam, the knockoff lever, the crank carrying said lever and the coiled spring engaging at one end an abutment moving with the crank and at its other end said lever for holding the latter yieldingly against the cam, substantially as and for the purpose set forth.

2. Asan improvement in valvegear, the combination of the knock-off cam,the knockoff lever, a pivoted block and a coiled spring between thelatter and said lever, substantially as and for the purpose shown.

off lever, the eccentric-actuated crank, the

bracket carried by the latter, the pivoted block on the bracket, the spring between the block and the knock-01f lever, and means to adjust the tension ofsaid-spring, substantially as andfor-the purpose shown.

5. As an improvement in valve gear, the combination-of the crank for rotating the valve, the latch lever to engage said crank,

the eccentric actuated crank carrying said lever the knock-off lever, also carried by said crank, and connected to-the latch lever, the governor-controlled means for moving said knockoff-lever in one direction, and a coiled spring to move itin the-opposite direction,

that engages saidknockoff lever at one end, and anabutment moving with the eccentric actuated crank, at its other end,substantially as and for the purpose set. forth.

In testimony that I claim the foregoing I have hereunto set-my hand this 20th day of June, A D. 1893.

CHAS. A. DIXON.

Witnesses:

DAVID BARCLAY, O. L. WARING. 

